Spark-plug



L .ORGENSOM SPARK PLUG.

APFfLlCATlnN HLED MAR. l5, 1919.

Patented sept. 21,1920.

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UNITEDi STATES PATENT oFFlcE. y

JOHN JORGENSON, 0F RACINE, 'WISCNSINZ SPARK-PLUG.

To all whom it may concern Be it known that I, JoHN JoRGnNsoN, a citizen of the United States and resident of Racine, in the county of Racine and State of Vi'sconsin, have invented new and useful Improvements in Spark-Plugs, of which the following is a description, reference being had to the accompanying drawings, which are apart ofV this specification.

This invention relates to improvements in spark plugs.

rl`he ordinary spark plug now in use is not provided with any means for indicating whether or not it is sparking within the cylinder of the engine -to which it is connected, and in multiple cylinder engines it is somewhat difficult to quickly tell which plug is not properly performing its function.

It is one of the objects of the present invention to overcome the .before mentioned objectionable features, and provide a spark plug in which visible means are provided for 'indicating whether or not the plug is properly doing its work. y i

A further object of the invention is to provide a spark-plug having a plurality of contacts located at its end which is adapted toY enter the engine cylinder so that an in- Y creased number of sparks will be provided for igniting thel charge within the engine.

A further object ofthe invention is to provide a spark plugin which a spark is visible between'the return'or vground electrode." l A further object .of the invention' is to provide a spark plug which isofvery simple construction Vand may be mounted in the ordinary manner upon an ordinary internal combustion engine.r

With the above and other objects in view. the inventionconsists of the improved spark plug and vits-parts and combinations as set forth in the Vclaims and all equivalents thereof.-

.` In the accompanying drawingV in which the same reference characters'indicate the Specification of Letters Patent. Patented Sept-, 21, 1920.

' Application led March 15, 1919.

Serial No. 282,911.

Fig. 5 is an inner end view of the sparking end of the plug showing a slightly modified form of sparking points; and

Fig. 6 is a vertical sectional view of a modified form of spark plug.

Referring to the drawing, the numeral 8 indicates the outer plug shell which is provided with a threaded portion 9 for connection with an engine, and also with a hexagonal portion 10 to permit the use of a wrench in threading the shell into the engine. The portion 11 of the shell extends vertically therethrough, and at its upper end portion is of larger diameter to form a shoulder 12 to receive a tubular clamping bolt 18.

lThe insulating member 14 preferably formed of mica or porcelain extends through the shell 8 and the tubular bolt 13, and is provided with an enlargementll which engages the shoulder 12. Copper washers 15 are preferably located between 'the enlargement 14 and the shoulder 12, andl between the enlargement 14 and the tubular nut 13, in order to form a gas tight connection between the insulating member and the shell. Said tubularl bolt 13 is threaded into the shell 8.

Y An entering' electrode 16 extends through the insulating member from its upper medial portion to its lower peripheral portion, and projects slightly below the inner end of the insulating, member. 1

The upper or outer. end of the entering electrode is connected to a binding. post 17 which is provided with the usual holding nut 18 and wire clamping nut 19. The insulating member is also provided with a ground o r return electrode 20 which eX- tends through'the insulating member from a medial portion thereof to its inner end near its periphery.' The upper end portion of this return electrode 2O is provided with an angular extension 20 which extends outwardly to the peripheral edge portion of the enlargement 14 andterminates at said periphery. Y The shell 8 is Yprovided with a conical opening 21r extending from its bore outwardly, and the annular extending end of the return electrode 20 terminates ata point centrally of the inner or smaller end of this conical opening to provide for the current of electricity returning to ground by jumping or arcing over the space between the end 21 Vand the casing `8, thus providing a 35 Y' eliminated, andthe holding nut 18 is adaptvisible means for determining whether or not the plug is arcing or sparking at its inner end. i

The inner end of the insulating member is provided with a plurality of supported i,

sparking points 22 mounted in the lower end portion of sai'd insulating member and projecting a slight distance inwardly therefrom. Said sparking points extend around the peripheral edge portion of the insulating member on opposite sides of the electrodes 16 and 2i) so that the curernt enten ing the plug by means of the electrode 16 will jump the spaces between said sparking points and return to ground through theV return electrode 2O and the plug casing. This construction provides for a plurality of sparks at the inner end of the plug on both sidesot the electrodes and also provides a visible spark between the outer end of the return electrode andthe plug shell 8. Fur- Y thermore, `the resistance to the passage of the current vcaused by the gap spaces beposition within the shell member 8.

tween the sparking points has a tendency to increase the sparking and to keep the sparking points clean and free from carbon.

In the modified form shown in Fig. 5, the sparking points are in the form of a circle of smallerpins spaced a proper distance apar't'to permit the current to jump from one pin to the other in completing its circuit;

The modified form shown in Fig.- 6 similar to the first mentioned form, with the exception that the shell tubular end 13 is ed to .hold the insulating member 14 in The lower end of this modiiied formfof insulating member 14" is provided'with a head 23 which bears against a washer Qiinterposed i between said head and the inner end Vof the plugshell 8. An insulating cap 25 covers the upper or outer end of the insulator and its innerend enters a recess A26 ormedin i the plug shell 8', and said inner end engages bindin post member 17 is provided with ag head 1 molded within the insulator member 14: to form airm connection therewith.

The electrodes 16 and '20 and thel sparking points 22 rif-this modified form vare substantially theV same as the form shown in the first form mentioned.

*From the foregoing description it will be VVseen'that the spark plug is of very simple construction, and `is `well adapted Vfor the purpose described, audit maybe easily seen whether or not the spark plugs are properly performing their function.

W'li'at l claim as my invention is:

LA spark plug, comprising a tubular plug shell, an insulating member extending therethrough, means for clamping lsaid insulating member to the plug shell, a pair of electrodes extending through the insulating member and terminating at their in# ner ends adjacent the inner end of the insulating member, a plurality of contact point members extending in spaced relation from one electrode to the other', said plug shell having a sight opening extending therethrough, the outer end of one ot the electrodes terminating at a point close to but spaced from the walls oit the plug shell forming said sight opening to form a visible supplemental spark gap therebetween, and a binding post mounted in the outer end portion oi the insulating member and connected to the outer end of the other electrode.

2. A spark plug comprising a plug shell member having a tubular bore, an insulating member extending therethrough and provided with an enlargement for firmly connecting the insulating member to the plug shell member, means for clamping the enlarged portion of the insulating member to the plug shell, a pair'of electrodes extending through the insulating member and terminating at their inner ends adjacent the inner peripheral edge of the insulating mem-V ber, a plurality of 'sparking `point members extending in spaced relation between the electrodes, said plug shell having a sight opening, the outer end portion of one of the electrodes terminating at a point adjacent to said sight opeuingbut spaced from the walls of the plug shell forming said opening to form a'visible supplemental spark gapv therebetween, a binding pest mounted in the outer end portion of the yinsulating member and connected to the louterV end of the other electrode, and a clamping nut mounted on said binding screw.

3. A spark plug comprising a plug shell member having a tubular shouldered bore and also having a sight opening extending approximately at'right angles to said bore, an insulatinglmember extending through the bore of the .plug shell and having a medial enlargement positioned adjacent the shtmldered portion of'thebore, a pair of sulating member and Vhaving a connection with the outer end portion ofthe other electrode. v

4. A spark plug, comprising a plug shell member having a bore and a sight opening, an insulating member extending through the bore of the plug shell member, an inner electrode extending through the insulating member and terminating at its inner end adjacent a peripheral portion of the inner end of the insulating member, a return electrode extending through the insulating member and terminating at its inner end adjacent a peripheral portion of the insulating member, the outer end portion of the return electrode terminating at a point adjacent to but spaced from the Walls of the plug shell forming the Vsight opening to form a visible supplemental spark gap therebetween, and a binding post mounted in the outer end portion of the insulating member and having a connection With the entering electrode. j

5. A spark plug, comprising a plug shell member having a bore and a conical sight opening, an insulating member extending through said bore and having an enlargement at its inner end which engages the inner end portion of the plug shell, an

insulating cap member extending over the outer end Vportion of said plug shell, a binding post mounted in the outer end portion of the insulating member and extending through the cap member, a holding nut threaded on the binding post and engaging the cap member, an entering electrode connected to the binding post and extending through the insulating member and terminating at the inner end of said insulating member adjacent a peripheral portion thereof, a return electrode member extending through the insulating member and terminating at its inner end adjacent a peripheral portion of the -inner end of the insulating member, the outer end of said return electrode extending through the enlargement and terminating at a point adjacent the Walls forming the sight opening of the plug case to form a visible supplemental spark gap therebetween, and a plurality of plug contact members mounted on the inner end portion of the insulating member and extending in spaced relation from one electrode to the other.

In testimony whereof I ax my signature.

JOHN JoRGENsoN. 

